Escalator linear belt handrail drive

ABSTRACT

An escalator handrail drive arrangement includes a drive belt ( 26 ) mounted within a drive housing ( 35 ). Pressure rollers ( 30 ) are mounted in pairs and pivotally attached to the drive housing. The pressure rollers bias a handrail ( 22 ) against the drive belt. The pressure roller arrangements are mounted at each axial end. A spring ( 44 ) biases the pressure roller arrangements against the handrail, with the spring being centered along the axial length of the pressure rollers. This spring is preferably mounted within the drive housing such that no additional space is required outwardly of the drive and roller arrangement to accommodate the spring.

This application relates to a belt handrail drive for an escalatorwherein the pressure rollers are mounted to the drive housing at bothaxial ends, with a centrally located spring.

Escalators typically have a handrail that is driven by drive rollersthrough a drive belt. To hold the handrail in good frictional contactwith the drive belt, pressure rollers are typically mounted on anopposed side of the handrail from the drive belt and spring biasedagainst the handrail.

In the prior art, the pressure rollers have typically been cantilevermounted. Further, the spring for biasing the pressure roller against thehandrail has been mounted outwardly of the roller axial length, at theend of a housing at which the pressure rollers are mounted. The springhas typically been mounted beneath the handrail, to bias the rollerupwardly. The pressure rollers are typically mounted in a plate whichpivots relative to a drive housing. Since the spring is outwardly of theaxial length of the roller, additional width is required. Further, sincethe spring is not centered on the roller, the force applied by thepressure roller is not equal along the length of the roller.

In the past, the rollers have sometimes tilted along an axis due to theposition of the spring. Further, unequal pressure along the width of theroller has sometimes resulted in uneven wear of the rollers andhandrail.

SUMMARY OF THE INVENTION

In the disclosed embodiment of this invention, the pressure rollers aremounted to the drive housing at both axial ends. The tilting describedabove is thus eliminated. Further, the spring is preferably mountedwithin the axial length of the roller. In this way, uneven wear andtilting as described above are eliminated.

Further, the spring is most preferably mounted within the drive housingsuch that no additional space is required to provide the spring for thepressure roller.

In a further feature, an adjustment screw can adjust the bias force fromthe spring. A stop is provided within the drive housing to limit theamount of tension that can be applied to the spring such that the forcecan be limited.

While the invention is described in an escalator, it should also beunderstood that the benefits for the pressure roller drive described inthis application would apply equally to other linear passenger conveyingmechanisms such as moving walk ways, etc.

These and other features of the present invention can be best understoodfrom the following specification and drawings, the following of which isa brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a portion of an escalator handrail drive.

FIG. 2 is a side view of the drive arrangement with a pressure rollerarrangement.

FIG. 3 is a cross-sectional view along line 3-3 as shown in FIG. 2.embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a handrail drive arrangement 20 including a handrail 22. Adrive input 24 drives a roller 25 to in turn drive a belt drive 26. Beltdrive 26 frictionally engages and drives handrail 22.

Pressure roller pairs 28 are biased upwardly as shown in FIG. 1 to holdthe handrail 22 against the belt 26. The pressure roller pairs 28 eachinclude a pair of pressure rollers 30 connected by pressure rollerhousings 32, and pivotally connected as shown at 34 to the drive housing35.

As shown in FIG. 2, there are several pressure roller pairs 32. Thepressure rollers are mounted slightly beneath the belt 26.

As shown in FIG. 3, the housing 32 includes two opposed side plates 48and 46. Rollers 30 are mounted between plates 48 and 46. Thus, therollers 30 are mounted at each axial end. Further, the pivotalconnection 34 connects plates 48 and 46. Adjustment bar 100 serves as areaction surface for a spring arrangement 43. Spring arrangement 43includes spring 44, and a member 45 which is pulled upwardly byadjustment of a screw 36 to adjust the force from the spring 44 againstthe bar 100. As is clear, the bar 100 is guided in slots 102 in sideplates of drive housing 35.

As can be appreciated in FIG. 3, the spring 44 thus biases the rollers30 upwardly with the side plates 48 and 46. Notably, the spring 44 iswithin the axial length of the rollers 30, and preferably is centered onthe axial length of the rollers 30. Moreover, the spring 44 is above thebelt 22 such that no additional space is required for the provision ofthe spring. Instead, the spring is actually incorporated within thedrive housing 35, and yet still biases the rollers against the handrail22.

Further, a stop 50 limits the amount of adjustment of the spring 44 byabutting a fixed surface 51 within the drive housing to limit the amountof force which can be applied to the spring through adjustment of thescrew 36.

Thus, the present invention provides an arrangement wherein the pressurerollers are spring biased by a centrally located spring, and along thelength of the roller. Moreover, the pressure roller is mounted on eachside, preventing the tilting and uneven wear which has been an issue inthe prior art. Further, the location of the spring provides a muchsmaller envelope and thus a reduced required space.

Although a preferred embodiment of this invention has been disclosed, aworker of ordinary skill in this art would recognize that certainmodifications would come within the scope of this invention. For thatreason, the following claims should be studied to determine the truescope and content of this invention.

1. A drive arrangement for a handrail comprising: a handrail to bedriven along a path of travel; a drive input driving a drive belt, saiddrive belt being in frictional engagement with said handrail; and atleast one pressure roller on an opposed side of said handrail from saiddrive belt, said pressure roller biasing said handrail against saiddrive belt, and said pressure roller extending along an axis of rotationbetween first and second ends, with said pressure roller being mountedat each of said first and second ends.
 2. An arrangement as set forth inclaim 1, wherein a spring biases said pressure roller against saidhandrail, with said spring being mounted along said axis of saidpressure roller, and between said first and second ends.
 3. Anarrangement as set forth in claim 2, wherein said spring is centeredbetween said first and second ends.
 4. An arrangement as set forth inclaim 2, wherein said spring is on an opposed side of said handrail fromsaid pressure roller.
 5. An arrangement as set forth in claim 2, whereinsaid drive input is mounted within a drive housing, said drive housingalso mounting said drive belt.
 6. An arrangement as set forth in claim5, wherein said drive housing receiving said bias spring, such that saidbias spring is within said drive housing, and on an opposed side of saidhandrail from said pressure roller.
 7. A conveyer as set forth in claim6, wherein an adjustment screw can be turned to adjust a force from saidbias spring.
 8. An arrangement as set forth in claim 7, wherein saidadjustment screw drives a spring holding member, said adjustment screwmoving a bar through said bias spring to in turn move said pressureroller pairs, and said bar being guided within said drive housing.
 9. Anarrangement as set forth in claim 1, wherein said pressure roller ismounted to a pressure roller housing at each of said first and secondends.
 10. An arrangement as set forth in claim 9, wherein there is apair of said pressure roller mounted to said pressure roller housing,said pressure roller housing being pivotally attached to said drivehousing.
 11. An arrangement as set forth in claim 1, wherein saidhandrail is part of a passenger conveyer.
 12. An arrangement as setforth in claim 11, wherein said passenger conveyer is an escalator.